Body condition and poxvirus infection predict circulating glucose levels in a colorful songbird that inhabits urban and rural environments. Issue 8 (9th June 2020)

• Record Type: Journal Article
• Authors: McGraw, Kevin J.; Chou, Katherine; Bridge, Annika; McGraw, Hannah C.; McGraw, Peyton R.; Simpson, Richard K.
• Is Part Of: Journal of experimental zoology. Volume 333:Issue 8(2020)
• Page Start: 561
• Page End: 568
• Publication Date: 2020-06-09
• Subjects: blood sugar -- disease -- Haemorhous mexicanus -- house finch -- wildlife health; Zoology -- Periodicals; Zoology; Animal Population Groups -- physiology; Zoology; Electronic journals; Periodical; Periodicals; 590
• DOI: 10.1002/jez.2391
• Languages: English
• ISSNs: 2471-5646

Abstract

Abstract: There is widespread contemporary interest in causes and consequences of blood glucose status in humans (e.g., links to diabetes and cardiovascular disease), but we know comparatively less about what underlies variation in glucose levels of wild animals. Several environmental factors, including diet, disease status, and habitat quality, may regulate glucose circulation, and we are in need of work that assesses many organismal traits simultaneously to understand the plasticity and predictability of glucose levels in ecological and evolutionary contexts. Here, we measured circulating glucose levels in a species of passerine bird (the house finch, Haemorhous mexicanus ) that has served as a valuable model for research on sexual selection, disease, and urban behavioral ecology, as these animals display sexually dichromatic ornamental coloration, harbor many infectious diseases (e.g., poxvirus, coccidiosis, mycoplasmal conjunctivitis), and reside in both natural habitats and cities. We tested the effects of sex, habitat type, body condition, coccidiosis and poxvirus infections, and expression of carotenoid plumage coloration on blood glucose concentrations and found that the body condition and poxvirus infection significantly predicted circulating glucose levels. Specifically, birds with higher blood glucose levels had higher body condition scores and were infected with poxvirus. This result is consistent with biomedical, domesticated‐animal, and wildlife‐rehabilitation findings, and the premise that glucose elevation is a physiological response to or indicator of infection and relative body weight. The fact that we failed to find links between glucose and our other measurements suggests that blood glucose levels can reveal some but not all aspects of organismal or environmental quality. Research Highlights: High blood glucose levels in house finches were associated with higher body condition and viral infection. These findings are consistent with the biomedical literature and suggest that blood glucose can reliably reveal wildlife health and condition. Abstract : Body condition and viral infection were significant predictors of circulating glucose levels in free‐ranging house finches.